As Eddie51 said, I also never throw away veg. I buy it in to use up on Sun roast & through the week, if I've any left over - which may be starting to look a bit wilted, I shred it all in a blender (any concoction of veg), add onion and put into a large pan with a homemade stock & season with herbs etc. Very filling, tasty, low fat & it goes a long way.
I always buy meat on the bone for Sun roast, I use the meat juices on the day for the gravy, but keep the bones/leftover meat in the fridge and boil these up again to make homemade stock.